A common architectural practice in the design of homes and buildings is to utilize skylights to provide or increase the amount of natural light to the interior. Skylights, being disposed generally on the roof tops of structures, are exposed to the damaging effects of falling debris, such as tree shedding (branches, tree nuts, etc.) and ice chunks from higher adjacent structures. Accordingly, skylights can be fitted with guards that protect the skylight from falling debris.
For flat roofs that are common to commercial and industrial buildings, skylights pose a safety hazard. It is common practice for maintenance personnel to access these roofs to perform general maintenance and repairs. The maintenance personnel have been known to accidentally fall onto skylights or, in some instances, intentionally sit on the skylights. As skylights age, they can deteriorate (e.g., turn brittle) and become more prone to breakage upon being flexed. Accordingly, every year there are many fall related fatalities associated with skylights, not only for maintenance personnel falling through the skylight, but also for persons within the building who happen to be below the skylight.
To address these safety hazards, the Occupational Safety and Health Administration (OSHA) considers rooftops of commercial/industrial buildings as a “walking-working surface” and has promulgated regulations regarding the guarding of skylights and other rooftop structures. These regulations are found generally at 29 CFR 1910.23, with skylights addressed more specifically at 29 CFR 1910.23(a)(4) and 29 CFR 1910.23(e)(8). The regulations at 29 CFR 1910.23 are hereby incorporated by reference herein in their entirety, except for express definitions contained therein.
The OSHA regulations have given rise to the commercial availability of skylight guard systems. Problems can arise with these conventional guard systems, particularly in the context of retrofitting the guard to an existing skylight. Some systems require that the guard be secured to the skylight using fasteners that penetrate the frame of the skylight; this can introduce leaks into the skylight. Other systems require no fasteners, but can be subject to forces that cause plastic deformation due to generation of yield stresses and/or creep stresses, causing the guard system to become loosened and insecure over time. Examples of such guards include U.S. Pat. No. 5,237,788 to Sandow and U.S. Pat. No. 6,209,271 to Kovacs, the disclosures of which are hereby incorporated by reference herein in their entirety except for express definitions and patent claims contained therein. Yield and creep stresses can be problematic for certain materials of choice, for example aluminum and aluminum alloys, which are easily extruded, are lightweight, and have excellent corrosion resistance for outdoor applications.
A skylight guard system addresses the shortcomings of conventional skylight guards would be a welcomed addition.